Molten metal containment structure having movable cover

An exemplary embodiment of the invention provides a molten metal containment structure, including a vessel having an internal volume for containing molten metal and an open upper end. The structure further includes a cover for the vessel having an underside facing the internal volume, the cover being movable between a closed position, covering the open upper end of the vessel with the underside of the cover, and an open position in which the cover is remote from the open upper end of the vessel to allow access to the internal volume from one side of the structure. The cover is attached to at least one lifting arm (preferably two or more) and at least on rotation control arm (preferably two or more). The lifting arm(s) operates to guide the cover from the open position to the closed position, and vice versa. The rotation control arm(s) operates to control pivoting of the cover during movement from the closed position to the open position, and vice versa, to prevent exposure of the underside of the cover, which in operation is very hot, to a person positioned adjacent to the structure at the aforesaid one side thereof. The lifting arm(s) and/or rotation control arm(s) provide a force that at least partially counterbalances a weight of the cover.